Accessible Low-Floor Bus: System Approach in France

1997 ◽  
Vol 1604 (1) ◽  
pp. 163-169
Author(s):  
Maryvonne Dejeammes
Keyword(s):  
System Approach ◽  
Urban Environments ◽  
Operating Conditions ◽  
Easy Access ◽  
Wheelchair User ◽  
Bus Stop ◽  
Reduced Mobility ◽  
Bus System

Low-floor bus design makes urban buses more accessible to people with reduced mobility. In France, as a result of the knowledge gained from using low-floor tramways, the use of low-floor buses within urban environments was considered. Requirements of people with reduced mobility for easy access and the necessary operating conditions are described, followed by an examination of the requirements for such a system in France: bus/infrastructure interface (access ramp and docking aid), bus stop design, and wheelchair user safety.

Optimal Placement of FACTS Devices for Voltage Stability Improvement with Economic Consideration Using Firefly Algorithm

2019 ◽  
Vol 14 (1) ◽  
pp. 5-11
Author(s):  
S. Rajasekaran ◽  
S. Muralidharan
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Firefly Algorithm ◽  
Transmission System ◽  
Operating Conditions ◽  
Optimal Placement ◽  
Voltage Collapse ◽  
Facts Devices ◽  
The Cost ◽  
Bus System

Background: Increasing power demand forces the power systems to operate at their maximum operating conditions. This leads the power system into voltage instability and causes voltage collapse. To avoid this problem, FACTS devices have been used in power systems to increase system stability with much reduced economical ratings. To achieve this, the FACTS devices must be placed in exact location. This paper presents Firefly Algorithm (FA) based optimization method to locate these devices of exact rating and least cost in the transmission system. Methods: Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) are the FACTS devices used in the proposed methodology to enhance the voltage stability of power systems. Considering two objectives of enhancing the voltage stability of the transmission system and minimizing the cost of the FACTS devices, the optimal ratings and cost were identified for the devices under consideration using Firefly algorithm as an optimization tool. Also, a model study had been done with four different cases such as normal case, line outage case, generator outage case and overloading case (140%) for IEEE 14,30,57 and 118 bus systems. Results: The optimal locations to install SVC and TCSC in IEEE 14, 30, 57 and 118 bus systems were evaluated with minimal L-indices and cost using the proposed Firefly algorithm. From the results, it could be inferred that the cost of installing TCSC in IEEE bus system is slightly higher than SVC.For showing the superiority of Firefly algorithm, the results were compared with the already published research finding where this problem was solved using Genetic algorithm and Particle Swarm Optimization. It was revealed that the proposed firefly algorithm gives better optimum solution in minimizing the L-index values for IEEE 30 Bus system. Conclusion: The optimal placement, rating and cost of installation of TCSC and SVC in standard IEEE bus systems which enhanced the voltage stability were evaluated in this work. The need of the FACTS devices was also tested during the abnormal cases such as line outage case, generator outage case and overloading case (140%) with the proposed Firefly algorithm. Outputs reveal that the recognized placement of SVC and TCSC reduces the probability of voltage collapse and cost of the devices in the transmission lines. The capability of Firefly algorithm was also ensured by comparing its results with the results of other algorithms.

Scheduling a Bus Fleet for Evacuation Planning Using Stop-Skipping Method

2021 ◽  
pp. 036119812110200
Author(s):  
Hu Zhao ◽  
Shumin Feng ◽  
Yusheng Ci
Keyword(s):  
Waiting Time ◽  
Ant Colony Algorithm ◽  
Programming Model ◽  
Peer To Peer ◽  
Mathematical Programming Model ◽  
Fleet Size ◽  
Bus Stop ◽  
Passenger Demand ◽  
Service Strategies ◽  
Bus System

Sudden passenger demand at a bus stop can lead to numerous passengers gathering at the stop, which can affect bus system operation. Bus system operators often deal with this problem by adopting peer-to-peer service, where empty buses are added to the fleet and dispatched directly to the stop where passengers are gathered (PG-stop). However, with this strategy, passengers at the PG-stop have a long waiting time to board a bus. Thus, this paper proposes a novel mathematical programming model to reduce the passenger waiting time at a bus stop. A more complete stop-skipping model that including four cases for passengers’ waiting time at bus stops is proposed in this study. The stop-skipping decision and fleet size are modeled as a dynamic program to obtain the optimal strategy that minimizes the passenger waiting time, and the optimization model is solved with an improved ant colony algorithm. The proposed strategy was implemented on a bus line in Harbin, China. The results show that, during the evacuation, using the stop-skipping strategy not only reduced the total waiting time for passengers but also decreased the proportion of passengers with a long waiting time (>6 min) at the stops. Compared with the habitual and peer-to-peer service strategies, the total waiting time for passengers is reduced by 31% and 23%, respectively. Additionally, the proportion of passengers with longer waiting time dropped to 43.19% by adopting the stop-skipping strategy, compared with 72.68% with the habitual strategy and 47.5% with the peer-to-peer service strategy.

Does the Burning of Moxa (Artemisia vulgaris) in traditional Chinese medicine constitute a health hazard?

2009 ◽  
Vol 27 (1) ◽  
pp. 16-20 ◽  
Author(s):  
John Wheeler ◽  
Belinda Coppock ◽  
Cecil Chen
Keyword(s):  
Carbon Monoxide ◽  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Health Hazard ◽  
Urban Environments ◽  
Operating Conditions ◽  
Therapeutic Modality ◽  
Worst Case ◽  
Safety Standards ◽  
Exposure Levels

Background Concerns have been expressed about potential toxicity of the smoke produced by the burning of moxa in traditional Chinese medicine. With the advent of strict anti-smoking legislation in the UK, it was decided to test the volatiles produced by moxibustion and compare them with current agreed safe exposure levels. Method Moxa, in the form of cigar shaped moxa “sticks” or “rolls”, was tested under International Organization for Standardization conditions in a tobacco testing laboratory, and the quantities of a number of pre-determined volatiles measured. The smoke tested was “sidestream smoke”, the smoke which arises from the burning tip of the moxa. The test results were then scaled up to reflect normal use and to provide direct comparisons with agreed national safety standards for both short- and long-term exposure levels. Results Levels of only two volatiles produced were equivalent or greater than the safe exposure levels, as was the carbon monoxide level reported, both as a consequence of using worst case assumptions for comparison. Under normal operating conditions neither volatile nor carbon monoxide would present a safety hazard. One group of chemicals tested, the aromatic amines, with known carcinogenic properties have no agreed safety levels. Results for these in the study compared favourably with background levels reported in urban environments. Conclusion There are no immediate concerns arising from the continued use of moxa as a therapeutic modality in traditional Chinese medicine. Further testing may be required to establish whether current recommendations for ventilation and cleansing of treatment room surfaces may need to be revised. Stronger recommendations may also be necessary on the inadvisability of using moxa on broken skin.

Engine Design Studies for a Silent Aircraft

2006 ◽  
Vol 129 (3) ◽  
pp. 479-487 ◽  
Author(s):  
Cesare A. Hall ◽  
Daniel Crichton
Keyword(s):  
Thermodynamic Cycle ◽  
Urban Environments ◽  
Operating Conditions ◽  
Speed Reduction ◽  
Fuel Burn ◽  
Engine Design ◽  
Low Altitude ◽  
Noise Benefits ◽  
Bypass Ratio ◽  
Maximum Thrust

The Silent Aircraft Initiative is a research project funded by the Cambridge-MIT Institute aimed at reducing aircraft noise to the point where it is imperceptible in the urban environments around airports. The propulsion system being developed for this project has a thermodynamic cycle based on an ultrahigh bypass ratio turbofan combined with a variable area exhaust nozzle and an embedded installation. This cycle has been matched to the flight mission and thrust requirements of an all-lifting body airframe, and through precise scheduling of the variable exhaust nozzle, the engine operating conditions have been optimized for maximum thrust at top-of-climb, minimum fuel consumption during cruise, and minimum jet noise at low altitude. This paper proposes engine mechanical arrangements that can meet the cycle requirements and, when installed in an appropriate airframe, will be quiet relative to current turbofans. To reduce the engine weight, a system with a gearbox, or some other form of shaft speed reduction device, is proposed. This is combined with a low-speed fan and a turbine with high gap-chord spacing to further reduce turbomachinery source noise. An engine configuration with three fans driven by a single core is also presented, and this is expected to have further weight, fuel burn, and noise benefits.

Engine Design Studies for a Silent Aircraft

2006 ◽  
Author(s):  
Cesare A. Hall ◽  
Daniel Crichton
Keyword(s):  
Thermodynamic Cycle ◽  
Urban Environments ◽  
Operating Conditions ◽  
Speed Reduction ◽  
Fuel Burn ◽  
Engine Design ◽  
Low Altitude ◽  
Noise Benefits ◽  
Bypass Ratio ◽  
Maximum Thrust

The Silent Aircraft Initiative is a research project funded by the Cambridge-MIT Institute aimed at reducing aircraft noise to the point where it is imperceptible in the urban environments around airports. The propulsion system being developed for this project has a thermodynamic cycle based on an ultra-high bypass ratio turbofan combined with a variable area exhaust nozzle and an embedded installation. This cycle has been matched to the flight mission and thrust requirements of an all-lifting body airframe, and through precise scheduling of the variable exhaust nozzle, the engine operating conditions have been optimized for maximum thrust at top-of-climb, minimum fuel consumption during cruise and minimum jet noise at low altitude. This paper proposes engine mechanical arrangements that can meet the cycle requirements and, when installed in an appropriate airframe, will be quiet relative to current turbofans. To reduce the engine weight a system with a gearbox, or some other form of shaft speed reduction device, is proposed. This is combined with a low-speed fan and a turbine with high gap-chord spacing to further reduce turbomachinery source noise. An engine configuration with three fans driven by a single core is also presented and this is expected to have further weight, fuel burn and noise benefits.

scholarly journals The outcome of natural honey used in chronic ulcers

2021 ◽  
Vol 12 (3) ◽  
pp. 1984-1989
Author(s):  
Nizam Ahmed ◽  
Aftab Alam Khanzada ◽  
Muhammad Rafique Joyo ◽  
Tanveer Afzal ◽  
Niaz Hussain keerio ◽  
...  
Keyword(s):  
Low Cost ◽  
Treatment Method ◽  
Easy Access ◽  
Diabetic Patients ◽  
Multiple Sources ◽  
Group A ◽  
Chronic Ulcers ◽  
Group B ◽  
Reduced Mobility ◽  
Natural Honey

The unique characteristics of natural honey obtained in any source in topical chronic nonhealing ulcers have been decreased discomfort, oedema, inflammation, deodorization, disinfect, neo-vascularization, collagen synthesis, granulation, epithelization and hence the ulcer treatment method. In that study, 200 patients were treated in a forward-looking, unrandomized experiment, with persistent, unhealing ulcers found in various areas of their body in the two groups keeping 100 in Group A and used honey dressing and Group B managed without using honey. Natural honey from multiple sources has been used. The main explanation for reduced mobility and loss of work illustrates productivity being pain and fever. The leading causes of healing delays were bacterial infection, necrotic tissue involvement, bedridden state, age, fatigue, Ulcer located near the joint. The quality, the simplicity of application and the efficiency make the control of recurrent nonhealing Ulcers easier for natural honey. For low cost, easy access, and improved healing make it a valuable option for natural honey to handle chronic, nonhealing ulcers, as well as healthy use in diabetic patients. 

Scope and limitations of ruthenium-catalyzed metathesis of simple polymer-bound alkenes

2001 ◽  
Vol 79 (5-6) ◽  
pp. 1049-1057 ◽  
Author(s):  
Peter G Breed ◽  
James A Ramsden ◽  
John M Brown
Keyword(s):  
Primary Alcohol ◽  
Butyl Ester ◽  
Operating Conditions ◽  
Allyl Ether ◽  
Side Chain ◽  
Ether Linkage ◽  
First Case ◽  
Gel Phase ◽  
Reduced Mobility ◽  
C Nmr

Synthetic procedures for the preparation of two types of functional resin are described, both based on 2% cross-linked polystyrene with a high density (>60%) of side-chains and terminated by a primary alcohol. In the first case the C11 side-chain is linked to the polymer through a sulfide, and in the second an ether linkage is employed to incorporate a (CH2CH2O)4 unit. In both cases the resins have 13C NMR spectra that are informative in the chain terminus region without special operating conditions. Model intermolecular metathesis reactions were carried out on allylcarbamic acid tert-butyl ester and various alkenes with Grubbs' catalyst. On the basis of these experiments, gel-phase metathesis was successfully demonstrated between a polymer-bound allyl ether and simple symmetrical disubstituted alkenes, monitoring the extent of reaction by 13C NMR. These reactions did not go to completion even with recycling and some evidence for competing interchain metathesis is presented, based on the increased broadening and reduced mobility of the ensuing polymer.Key words: alkene metathesis, ruthenium, gel-phase, 13C NMR.

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